CN101903446A - Halogen-free flame retardant thermoplastic polyurethane - Google Patents

Abstract

The invention provides a halogen-free flame-retardant thermoplastic polyurethane composite resin composition. The halogen-free flame-retardant thermoplastic polyurethane composite resin composition can improve the flame retardancy and burning dripping property of thermoplastic polyurethane resin by forming required charcoal when burning, which uses phosphonite, diphosphonite and/or The polymers obtained from them; dipentaerythritol; talc; melamine derivatives, etc. are used as flame retardants to replace halogen-containing flame retardants.

Description

Halogen-free flame retardant thermoplastic polyurethane

Background of the invention

technical field

The invention relates to a halogen-free flame-retardant thermoplastic polyurethane composite resin composition. More specifically, the present invention relates to a flame retardant thermoplastic polyurethane composite resin composition capable of improving the flame retardancy and flaming-drip of a thermoplastic polyurethane resin by forming desired char when burned, wherein Phosphonites, diphosphonites and/or polymers derived therefrom; dipentaerythritol; talc; melamine derivatives, etc. are used as flame retardants instead of halogen-containing flame retardants.

Background technique

Generally, thermoplastic polyurethane resins have good mechanical properties (such as high wear resistance) and high elasticity, and are used to prepare products by methods such as injection molding, extrusion molding, etc., unlike traditional thermosetting resins (that is, elastomers such as cross-linked joint rubber), and because of its good formability, it has been used in many industrial fields, such as automobiles, electric wires, pneumatic hoses, shoes, etc. However, thermoplastic polyurethane resins have poor flame retardancy, and thus have limited applications in some fields requiring high flame retardancy. Accordingly, methods of imparting flame retardancy to such thermoplastic polyurethane resins have been developed, in particular, methods of adding flame retardants to the resins are mainly used. Since the addition of flame retardants may reduce the mechanical properties of thermoplastic polyurethane, such as elongation at break, rebound elasticity, elastic modulus, abrasion resistance, etc., it is preferable to add flame retardants to the resin in as small a quantity as possible so that the properties are lost minimize. At the same time, thermoplastic polyurethane will decompose into low-molecular-weight molten substances after burning, which will cause burning and dripping. In this case, if a fire breaks out, burning drips may spread the fire. So, improving the occurrence of burning drips during burning is one of the many important things to consider when developing thermoplastic polyurethanes.

One way to improve the flame retardancy of thermoplastic polyurethane resins is to use halogen-containing flame retardants alone or together with metal oxides such as antimony oxide and the like. However, it is difficult to use this resin using a halogen-containing flame retardant for some applications due to its smoke (generated by combustion) and aggressiveness. Therefore, in order to solve the problems caused by the use of halogen-containing flame retardants, research and development of flame-retardant thermoplastic polyurethane resins using halogen-free flame retardants have recently been initiated.

For example, U.S. Patent No, 4,413,101 discloses a thermoplastic polyurethane resin, which uses high molecular weight resins including polyaryl phosphonate and polyaryl phosphonate carbonate as a flame retardant in an amount of 20 to 40 wt. parts, where the oxygen index is increased to improve flame retardancy. But it does not deal with physical properties and burning dripping.

Meanwhile, U.S. Patent No, 4,542,170 discloses improved flame retardants by using amino-s-triazine valeric acid (PENTATE) salts, and nitrogen-containing phosphates (such as amine phosphate, ammonium phosphate, and ammonium polyphosphate) as flame retardants. Flame retardancy and burning drip properties of thermoplastic polyurethanes. However, it was found that this method resulted in a significant reduction in mechanical properties such as tensile strength.

U.S. Patent No. 5,110,850 also discloses a flame-retardant thermoplastic polyurethane using only melamine as a flame retardant, wherein the flame retardancy is improved and reaches the UL (Underwriter's Laboratory) grade of UL 94-VO. However, this method does not address combustion dripping.

Therefore, there is a need to provide a flame-retardant thermoplastic polyurethane resin capable of improving burning dripping and flame retardancy while maintaining mechanical properties. In addition, there is a need for a resin having higher flame retardancy than known resins.

Summary of the invention

Accordingly, in order to solve the above-mentioned problems existing in the prior art, the inventors of the present invention added phosphonite, diphosphonite and/or the polymer obtained therefrom to thermoplastic polyurethane resin; dipentaerythritol; talc ; Melamine derivatives are used as flame retardants instead of halogen-containing flame retardants to develop a flame-retardant thermoplastic polyurethane composition. The flame retardant thermoplastic polyurethane composition has self-extinguishing properties, flame retardancy (higher than conventional compositions) and improved burning dripping properties.

Accordingly, the present invention is directed to providing a flame-retardant thermoplastic polyurethane resin composition which is highly self-extinguishable when burned and which can improve flame retardancy and burning dripping properties.

According to one aspect of the present invention, there is provided a flame-retardant thermoplastic polyurethane resin composition, comprising: 35 to 85 wt% of thermoplastic polyurethane resin, the diisocyanate of the polyurethane resin and the alcohol group included in the diol and polyol 0.5 to 15 wt% of organophosphorus flame retardant; 0.5 to 10 wt% of dipentaerythritol; 0.5 to 5 wt% of talc; and 5 to 35 wt% of melamine derivatives.

The halogen-free flame-retardant thermoplastic polyurethane composite resin composition of the present invention is environmentally friendly due to its own improved flame retardancy and improved burning dripping properties. Therefore, the application of the polyurethane resin composition to electric wire insulators, automotive interior materials, and the like can be expected.

Detailed description of the invention

Hereinafter, the present invention will be described in detail.

The invention relates to a flame-retardant thermoplastic polyurethane composite resin composition, which can solve the problems of flame retardancy and burning dripping of thermoplastic polyurethane resin by forming required charcoal during combustion, wherein a halogen-free flame retardant is combined with thermoplastic polyurethane used with resin.

The thermoplastic polyurethane resin used in the present invention includes hard segments and soft segments. The hard segment is obtained by reacting a diisocyanate with a diol of a chain extender. The soft segment is obtained by the reaction of polyol and diisocyanate, and the characteristics of the segment are determined by the type of polyol used.

The diisocyanate may be selected from one or a combination of the following materials, including: aromatic diisocyanate, aliphatic diisocyanate and cycloaliphatic diisocyanate. Aromatic diisocyanates include 1,4-phenylene diisocyanate; 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, or mixtures thereof; 2,2-methylene diphenylene diisocyanate, 2,4'-methylene diphenylene diisocyanate, or 4,4'-methylene diphenylene diisocyanate; and naphthylene diisocyanate. The aliphatic diisocyanate or cycloaliphatic diisocyanate may include cyclohexane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and the like.

As the dihydric alcohol of the chain extender, one or a combination of the following materials can be used, including: ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol , 2-methylpentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and neopentyl glycol.

Polyols may include polyester polyols, polyether polyols, and the like. Polyester polyols are prepared by reacting at least one dicarboxylic acid with at least one diol. Dicarboxylic acids include adipic acid, sebacic acid, suberic acid, methyladipic acid, glutaric acid, azelaic acid, etc.; dihydric alcohols include ethylene glycol, 1,3- or 1,2- Propylene glycol, 1,4-butanediol, 2-methylpentanediol, 1,5-pentanediol, 1,6-hexanediol, and the like. Furthermore, cyclic carbonates and the like, such as ε-caprolactone, can also be used to prepare polyester polyols. In particular, the polyester polyols mainly used are poly(ethylene adipate), poly(1,4-butylene adipate), or mixtures thereof, and poly(ε-caprolactone ) is also the main polyester polyol used.

Polyether polyols are prepared by addition polymerization of alkylene oxides. The alkylene oxide usable in the present invention includes ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, and the like. In particular, polyether polyols mainly used include poly(propylene oxide) glycol, poly(tetramethylene ether) glycol, or mixtures thereof. The polyol used for the soft segment of thermoplastic polyurethane preferably has a molecular weight of 500 to 8000, more preferably has a molecular weight of 800 to 5000.

Generally, catalysts for thermoplastic polyurethane resins can be tertiary amine-based catalysts or organometallic compounds. Tertiary amine-based catalysts can be selected from the group consisting of: triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N, N'-dimethylpiperazine, 2-(dimethylaminoethyl oxy)ethanol and diazabicyclo(2,2,2)-octane and the like; and organometallic compounds may be selected from the group consisting of: tin diacetate, tin dioctoate, tin dilaurate and dilaurate dibutyltin acid, etc. Preferably, the organometallic compounds may be used alone, or in admixture of two or more.

When preparing thermoplastic polyurethane resins, the equivalent ratio of diisocyanate groups (NCO) to alcohol groups (ie, alcohol groups (OH) included in diols and polyols for preparing thermoplastic polyurethane resins) is preferably 0.95 to 1.10, more preferably 0.96 to 1.05, most preferably 0.97 to 1.03.

If the equivalent ratio is less than 0.95, the molecular weight of the resin will be low, thereby degrading basic physical properties. On the other hand, an equivalence ratio greater than 1.10 also causes the same problem.

The polymerization reaction of the thermoplastic polyurethane resin can be carried out by a method using a batch reactor or a continuous reaction extruder. In the process using a batch reactor, the reactants are charged into the reactor, reacted to a certain extent, then discharged, and then heat treated. Meanwhile, in the method of using a continuous reaction extruder, the raw material is fed into the extruder from the raw material storage tank through the weighing system, and then the reaction is completed in the extruder. The process using a continuous reaction extruder is more preferred than the process using a batch reactor because the uniform heat transfer enables this process to result in a better uniformity of product quality.

In the method of producing a thermoplastic polyurethane resin using a continuous reaction extruder, the temperature of the extruder is preferably 150 to 250°C, more preferably 170 to 210°C.

In the present invention, the preferred amount of thermoplastic polyurethane resin is 35 to 80 wt%, more preferably 50 to 70 wt%. If the content is less than 35 wt%, the mechanical properties of the flame retardant thermoplastic resin composition will be reduced, on the other hand, if the content is more than 80 wt%, sufficient flame retardant effect cannot be achieved.

Also, in order to obtain the flame-retardant polyurethane composition of the present invention having better physical properties and processability, it is preferable that the thermoplastic polyurethane resin used for melt-kneading has a molecular weight of 100,000 to 700,000, more preferably 200,000 to 500,000. The above molecular weight is an average molecular weight measured using GPC (Gel Permeation Chromatography).

It is generally believed that phosphorus-based flame retardants interfere with the decomposition of the concentrated phase and increase the formation of char during combustion, thereby imparting flame retardancy to the resin, and in particular, are very effective for resins with high oxygen content, such as cellulose or thermoplastic polyurethane resin. The layer containing charred resin produced by combustion is char. The formation of char prevents the contact between the resin and the gases produced by the decomposition of the resin, thereby preventing the spread of the fire. The above-mentioned phosphorus-based flame retardants produce metaphosphoric acid, polymetaphosphoric acid, etc. by pyrolysis when burned, and have high flame retardancy because of a protective layer formed of a phosphoric acid layer and char produced by dehydrogenation of polymetaphosphoric acid. Therefore, phosphorus-based flame retardants are used in various resins. The organophosphorous flame retardant in the present invention can be one or two or more compounds selected from the following group of substances, including: phosphonites, diphosphonites and their polymers, and more Specifically, it may be a substance represented by the following formula:

Formula 1

Formula 2

The organophosphorous flame retardant of the present invention includes the phosphonite represented by formula 1, the diphosphonite represented by formula 2, and/or their polymers. In formulas 1 and 2, both ^R1 and ^R2 represent C1 to C6 alkyl groups, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl or benzene M represents calcium, aluminum or zinc; R ³ represents a linear or branched C1 to C10 alkylene group (for example: methylene, ethylene, n-propylene, isopropylene, n-butylene group, tert-butylene, n-pentylene, n-octylene or n-dodecyl), C6 to C10 arylene (for example: phenylene or naphthylene), C6 to C10 alkyl Arylene (for example: methylphenylene, ethylphenylene, tert-butylphenylene, methylnaphthylene, ethylnaphthylene, tert-butylnaphthylene) or C6 to C10 aromatic m represents 2 or 3; n represents 1 or 3; and x represents 1 or 2.

More preferably, Exolit OP is used as the organophosphorus flame retardant. It is possible to achieve high flame retardancy with only a small amount of this phosphorus-based flame retardant. Adding a small amount of phosphorus-based flame retardant can minimize the reduction of resin physical properties and effectively form char. Also, dipentaerythritol (C ₁₀ H ₂₂ O ₇ ) can enhance flame retardancy due to efficient char formation, and can expand to about 200 times its original size. However, the flame retardancy of thermoplastic polyurethane compositions prepared using only phosphonites, diphosphonites and their polymers, and dipentaerythritol is not sufficient.

Therefore, in the present invention, in order to improve burning dripping during combustion, melamine-based flame retardants, such as melamine derivatives, are used with phosphonites, diphosphonites and polymers derived therefrom, and pentaerythritol mixed. It is known that melamine-based flame retardants are less toxic, easier to handle, and generate less toxic gas than halogen-containing flame retardants, and thus are harmless to humans and the environment. Melamine cyanuric acid, melamine phosphate, melamine polyphosphate, and melamine borate are the main melamine-based flame retardants used. However, like phosphorus-based flame retardants, the use of melamine-based flame retardants alone in thermoplastic polyurethane resins can produce flame retardancy to a certain extent but cause burning drips. The flame retardancy of the thermoplastic polyurethane resin thus obtained is also insufficient.

As mentioned above, if one selected from phosphonite, diphosphonite and their polymers is used alone, each of two or more organophosphorus flame retardants, pentaerythritol or melamine-based flame retardants is used alone As a flame retardant for thermoplastic polyurethane resins, it is difficult to obtain a flame-retardant thermoplastic polyurethane composite resin composition having sufficient self-extinguishing properties and no burning drip. However, if a mixture of these three flame retardants is used, an expandable char layer is formed due to the synergistic effect, which in turn prevents the expansion of oxygen and heat. Then, the improvement of flame retardancy and burning drip can significantly improve the flame retardancy of TPU resin. In addition, if talc is further added to the composition, the flame retardancy will be further improved, so even a sample with a thickness of 1 mm can satisfy UL94 VO.

In particular, the problem of burning dripping can be solved by using a flame-retardant synergistic effect of one or two or more organophosphorus-based flame retardants with a mixture of pentaerythritol and melamine-based flame retardants. The agent is selected from phosphonites, diphosphonites and polymers thereof. Moreover, the use of phosphorus-based flame retardants in combination with nitrogen compounds (compared to the use of phosphorus-based flame retardants alone) can generate phosphoric acid amides during combustion, thereby forming an expandable char layer with increased thickness to effectively prevent the material from burning. expansion of heat and oxygen. In addition, if talc is further added, the effect of preventing heat and oxygen transfer will be enhanced. In the present invention, the preferred amount of one or two or more organophosphorous flame retardants selected from phosphonites, diphosphonites and polymers obtained therefrom is 0.5 to 15 wt%, more preferably 2 to 10 wt%. If the content is less than 0.5 wt%, the problem of burning and dripping during combustion cannot be solved. On the other hand, if the content is higher than 15 wt%, the mechanical properties will be greatly reduced.

Meanwhile, in the present invention, the preferred amount of the melamine derivative is 5 to 35 wt%, more preferably 15 to 30 wt%. If the content is less than 5% by weight, effective expandable char cannot be formed in combustion, thereby reducing flame retardancy. On the other hand, if the content is higher than 50wt%, the mechanical properties will be greatly reduced. For pentaerythritol, it is preferably used in an amount of 0.5 to 10 wt%, more preferably 2 to 8 wt%. If the content is less than 0.5 wt%, high flame retardancy cannot be obtained due to the inability to form a sufficient char layer, on the other hand, if the content is higher than 10 wt%, the mechanical properties will be greatly reduced.

In addition, in the present invention, talc is preferably used in an amount of 0.5 to 5 wt%, more preferably 1 to 4 wt%. If the content is less than 0.5 wt%, the effect of improving the flame retardancy cannot be achieved. On the other hand, if the content is higher than 5 wt%, the mechanical properties will be greatly reduced.

For improving the flame retardancy of thermoplastic resins, the particle size of the flame retardant is very important because it has a great influence on the mechanical properties of the final flame retardant resin. It is generally believed that the smaller the particle size, the better the mechanical properties and flame retardancy. The particle size of the flame retardant is preferably 1 to 60 μm, more preferably 1 to 40 μm. Here, a particle size larger than 60 μm is not preferable because it may cause difficulty in dispersion and decrease in flame retardancy.

In addition to the above flame retardant, the flame retardant thermoplastic polyurethane of the present invention may further include at least one additive selected from antioxidants, light stabilizers, lubricants, reinforcing agents, pigments, colorants and plasticizers. The use amount of the additive is within the range not to reduce the physical properties of the resin of the present invention.

The flame-retardant thermoplastic polyurethane synthetic resin of the present invention can be prepared by equipment capable of effectively dispersing a flame retardant in a thermoplastic polyurethane resin at a temperature higher than the melting point of the thermoplastic polyurethane resin. In general, thermoplastic polyurethane resins have a melting point of 150 to 250° C., and the melting point depends on the thermoplastic polyurethane resin used. As equipment for dispersing the flame retardant in the resin, it is possible to use: a mixer (such as a Banbury mixer), a roll-mill (roll-mill), a continuous kneader, a single-screw extruder, a twin-screw extruder, etc. In view of melt-kneading performance and productivity, the most preferable equipment is a twin-screw extruder. In particular, better effects may be obtained by using elements that improve the melt-kneading performance of the twin-screw extruder, that is, kneading elements and reverse-phase kneading elements.

In the present invention, a thermoplastic polyurethane resin and a halogen-free flame retardant are melt-kneaded using a twin-screw extruder. The molten output from the extruder die is then cooled through a cooling tank before being pelletized. The obtained halogen-free flame-retardant thermoplastic polyurethane composition was injection molded by using an injection molding machine, and was sufficiently stabilized at room temperature. Then, various mechanical properties and flame retardancy were tested.

As shown by the test results, the flame-retardant thermoplastic polyurethane composite resin composition of the present invention has high flame retardancy, significantly improved burning dripping property, and improved mechanical properties. Therefore, the composition is expected to be very useful in wire insulators, automotive interior materials and the like.

Hereinafter, details of the present invention will be described in detail with reference to the following examples. However, the following examples are merely exemplary, and the scope of protection of the present invention is not limited thereto.

Preparation Example

The thermoplastic polyurethane resin used in the present invention is a polyether-based thermoplastic polyurethane resin, which has a Shore hardness of 85A. Base diphenyl diisocyanate, and 1,4-butanediol are introduced into a continuous reaction extruder (Wemer & Pfleiderer ZSK 58 twin-screw extruder), and the mixture is obtained by polymerizing the mixture at 190-220°C. Here, the extruder was equipped with a metering device and had a kneading section with a size of 30% of the total screw area. The thermoplastic polyurethane resin polymerized in the continuous reaction extruder was pelletized by a pelletizer, and then dried at 70°C for 5 hours using a dehumidification dryer (Conair SC60, dew point of inlet air = -50°C). Then, the thermoplastic polyurethane resin was dried at 70° C. for 15 hours and used in combination with a flame retardant (NCO/OH=0.99; MW=250,000).

Comparative Example 1

70wt% thermoplastic polyurethane resin and 30wt% melamine cyanurate were melt-kneaded at 170-200°C using a twin-screw extruder. The molten output from the extruder die is then cooled through a cooling tank before being pelletized. The obtained thermoplastic polyurethane composition was made into a test sample using an injection molding machine, and was sufficiently stabilized. Next, on this sample, mechanical properties and flame retardancy were tested according to the following measurement methods. The results are shown in Table 1.

Comparative Example 2

In the same manner as in Comparative Example 1, a test sample was prepared from 65wt% thermoplastic polyurethane resin, 25wt% melamine cyanurate, and 10wt% Exolit OP, and was sufficiently stabilized. Next, on this sample, mechanical properties and flame retardancy were tested according to the following measurement methods. The results are shown in Table 1.

Comparative Example 3

In the same manner as in Comparative Example 1, a test sample was prepared from 75 wt% thermoplastic polyurethane resin, 20 wt% melamine cyanurate, and 5 wt% dipentaerythritol, and was sufficiently stabilized. Next, on this sample, mechanical properties and flame retardancy were tested according to the following measurement methods. The results are shown in Table 1.

Comparative Example 4

In the same manner as in Comparative Example 1, a test sample was prepared from 65 wt% thermoplastic polyurethane resin, 20 wt% melamine cyanurate, 10 wt% Exolit OP, and 5 wt% dipentaerythritol, and was sufficiently stabilized. Next, on this sample, mechanical properties and flame retardancy were tested according to the following measurement methods. The results are shown in Table 1.

Example 1

In the same manner as Comparative Example 1, a test sample was prepared from 60wt% thermoplastic polyurethane resin, 20wt% melamine cyanurate, 10wt% Exolit OP (Clarian), 5wt% dipentaerythritol and 5wt% talc, and fully stabilized. Next, on this sample, mechanical properties and flame retardancy were tested according to the following measurement methods. The results are shown in Table 1.

Example 2

In the same manner as Comparative Example 1, a test sample was prepared from 66 wt% of thermoplastic polyurethane resin, 20 wt% of melamine cyanurate, 7 wt% of Exolit OP (Clarian), 5 wt% of dipentaerythritol and 2 wt% of talc, and fully stabilized. Next, on this sample, mechanical properties and flame retardancy were tested according to the following measurement methods. The results are shown in Table 1.

Example 3

In the same manner as in Comparative Example 1, a test sample was prepared from 55wt% thermoplastic polyurethane resin, 30wt% melamine cyanurate, 7wt% Exolit OP (Clarian), 5wt% dipentaerythritol and 3wt% talc, and fully stabilized. Next, on this sample, mechanical properties and flame retardancy were tested according to the following measurement methods. The results are shown in Table 1.

Example 4

In the same manner as Comparative Example 1, a test sample was prepared from 60wt% thermoplastic polyurethane resin, 25wt% melamine cyanurate, 10wt% Exolit OP (Clarian), 7wt% dipentaerythritol and 3wt% talc, and fully stabilized. Next, on this sample, mechanical properties and flame retardancy were tested according to the following measurement methods. The results are shown in Table 1.

Experimental example

The performance of any thermoplastic polyurethane obtained by embodiments 1 to 4 and comparative examples 1 to 4 is measured by the following method:

(1) Tensile strength and elongation

Tensile strength and elongation at break were measured according to ASTM D412.

(2) Smoldering performance

According to the vertical burning test of UL (Underwriter's Laboratory) 94, the flame retardancy of the sample is measured (thickness: 3mm, width: 12.7mm, and length: 127mm; and thickness: 1mm, width: 12.7mm, and length: 127mm) . In the measurement, record the extinguishing time (t1) after burning the sample with a flame for 10 seconds, and then record the extinguishing time (t2) after burning the sample with a flame for 10 seconds. Here, when the sum of t1 and t2 does not exceed 30 seconds, the flame retardancy level is V1 or V2, and when the sum is less than 10 seconds, the flame retardancy level is V0. Similarly, when the absorbent cotton placed at the bottom burns due to burning and dripping, the flame-retardant grade is V2, and conversely, when the cotton does not burn, the flame-retardant grade is V0 or V1. Likewise, in the UL 94 vertical burn test, the number of drips is also measured.

Table 1

TUP: polyester-based thermoplastic polyurethane resin (hardness: 87A), commercially available from SK Chemicals

MCy: melamine cyanurate, commercially available from Budenheim, particle size: 30 μm

Dipentaerythritol: commercially available from Perstopr, particle size: 40 μm

Exolit OP: Particle size: 40μm

Talc: commercially available from Rexm, particle size: 30 μm

As shown in Table 1, compared with the halogen-free flame-retardant thermoplastic polyurethane composite resin compositions of Comparative Examples 1 to 4, the halogen-free flame-retardant thermoplastic polyurethane composite resin compositions in Examples 1 to 4 showed high flame retardancy (flame retardant grade is V0, even when the thickness is 1mm), and the burning dripping when burning is improved.

Although exemplary embodiments of the present invention have been described for illustrative purposes, those skilled in the art will understand that various modifications may be made, adding and replace.

Claims (12)

1. halogen-free fire retardation thermoplastic polyurethane composite resin composition comprises:

35 to 85wt% TPU(Thermoplastic polyurethanes), wherein vulcabond is 0.95 to 1.10 with the equivalence ratio that is included in the alcohol groups in dibasic alcohol and the polyvalent alcohol;

0.5 organic phosphorus flame retardant to 15wt%;

0.5 Dipentaerythritol to 10wt%;

0.5 talcum to 5wt%; With

5 to 35wt% melamine derivative.

2. the described composition of claim 1, wherein said polyvalent alcohol are polyester polyol or polyether glycol and have 500 to 8000 molecular weight.

3. the described composition of claim 1, the molecular weight of wherein said TPU(Thermoplastic polyurethanes) is 100,000 to 700,000.

4. a kind of, the mixture of two or more below the described composition of claim 1, wherein said organic phosphorus flame retardant are selected from the group: phosphinate, two phosphinates and their polymkeric substance.

5. the described composition of claim 4, wherein said phosphinate as shown in Equation 1 and described two phosphinates as shown in Equation 2:

Formula 1

Formula 2

Wherein, R ¹And R ²All represent C1 to C6 alkyl, for example, methyl, ethyl, n-propyl, sec.-propyl, normal-butyl, the tertiary butyl, n-pentyl or phenyl; R ³C1 to the C10 alkylidene group of representing line style or side chain (for example: methylene radical, ethylidene, inferior n-propyl, isopropylidene, inferior normal-butyl, the inferior tertiary butyl, inferior n-pentyl, inferior n-octyl or inferior dodecyl), the arylidene of C6 to C10 (for example: phenylene or naphthylidene), the alkyl arylene of C6 to C10 (for example: methylphenylene, the ethyl phenylene, tertiary butyl phenylene, the methyl naphthylidene, the ethyl naphthylidene, tertiary butyl naphthylidene) or the aryl alkylene of C6 to C10 (for example: phenylmethylene, the phenyl ethylidene, phenyl propylidene or phenyl butylidene); M represents calcium, aluminium or zinc; M represents 2 or 3; N represents 1 or 3; And x represents 1 or 2.

6. the described composition of claim 1, wherein said melamine derivative is selected from melamine cyanurate, melamine phosphate, polyphosphoric acid melamine and boric acid trimeric cyanamide.

7. the described composition of claim 1, the add-on of wherein said TPU(Thermoplastic polyurethanes) are 50 to 70wt%.

8. the described composition of claim 1, the add-on of wherein said organic phosphorus flame retardant are 2 to 10wt%.

9. the described composition of claim 1, the add-on of wherein said melamine derivative are 15 to 30wt%.

10. the described composition of claim 1, the add-on of wherein said Dipentaerythritol are 2 to 8wt%.

11. the described composition of claim 1, wherein said steatitic add-on are 1 to 4wt%.

12. each described composition in the claim 1 to 11, wherein the granularity of fire retardant is 1 to 60 μ m.